Thermostatic damper control



May 28, 1957 c. B. COSELMAN THERMOSTATIC DAMPER CONTROL Filed Jan. 6, 1955 2 Sheets-Sheet l IN VEN TOR. BY ;m

Olin/on B. Case/man y 1957 c. B. COSELMAN 2,793,811

THERMOSTATIC DAMPER CONTROL Filed Jan. 6, 1955 2 Sheets-Sheet I2 Fig.4

Fig. 5

Fig. 6

IN V EN TOR.

Clinton 3. Case/man United States Patent THERMOSTATIC DAMPER CONTROL Clinton B. Coselman, Seattle, Wash, assignor to C. B. Coselman, Incorporated, Seattle, Wash., a corporation of Washington Application January 6, 1955, Serial No. 480,090

1 Claim. 01. 236-) This invention relates to new and useful improvements in heater controls, and more particularly to an improved thermostatic damper control for heaters.

The primary object of this invention is to provide an improved thermostatic damper control for air-tight type heaters whereby heaters of the wood burning type may have the draft thereof automatically controlled so that 1 the heat emitted from such heaters may be controlled within a general range.

Another object of this invention is to provide an iml proved thermostatic damper control which is so con-" structed whereby it may be attached to casings of airtight wood burning type heaters so that the heat emitted from the firebox of the heater may be effectively con trolled by varying the draft thereof.

Another object of this invention is to provide a damper control of the thermostatic type, the damper control including a shield selectively positionable between the thermostatic element of the thermostatic damper control and the firebox of a heater to which it is attached wheresible, to pass said gases out the chimney, preventing the accumulation of sufiicient gases to cause an explosion when combustion starts.

A further object of this invention is to provide an improved draft construction for an air-tight heater, the draft construction including a draft duct securable to a firebox and housing the normal draft opening thereof,

the draft duct being provided with an opening through a casing of the heater with the opening being automatic-ally controlled through the use of a damper.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanyir'ig drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a top plan view of a heater employing the thermostatic damper control which is the subject of this invention, the cover for the heater being omitted in order to show the details of the control;

Figure 2 is an elevational view of the heater of Figure l with a portion of the casing thereof broken away in order to clearly illustrate the relationship of the thermostatic damper control with respect to the damper and draft assembly of the heater;

Figure 3 is an enlarged fragmentary sectional view' taken'substantially upon the plane indicated by the section line 3-3 of Figure 1 and shows more clearly the details of the draft assemblyand the damper;

Figure 4 is an enlarged fragmentary top plan view of the heater of Figure l in the vicinity of the thermostatic control, the cover of the heater being omitted in order to clearly illustrate the details of the thermostatic control;

Figure 5 is an enlarged fragmentary vertical sectional view. taken substantially upon the plane indicated by the section line 55 of Figure 4 and shows'the general mounting of the bimetallic element which controls the Patented May 28, 1957 operation of the thermostatic damper control, an alter-v nate position of the shield for the bimetallic element being shown in broken lines;

Figure 6 is an enlarged fragmentary vertical sectional view taken along a vertical plane through the outer casing substantially upon the plane indicated by the section line 6-6 of Figure 7 and shows the details of the means 1 for adjustably positioning the mounting arm for the shield;

Figure 7 is an enlarged fragmentary front elevational view of the casing in the vicinity of the thermostatic con-- r trol and shows 'the arrangement of the control knobs thereof and a cooling opening for the bimetallic ele-- ment; and

Figure 8 is an enlarged fragmentary vertical sectional view. taken substantially upon the plane indicated by the' section line 8-8 of Figure 3 and shows further the dc! tails of thedamper construction.

Referring now to the drawings in detail, it will be seen. that there is best illustrated in Figures 1 and 2 a generally air-tight wood burning heaterwhich is referred to in general by the reference numeral 10. The heater 10 includes a firebox 12 which is provided at one end thereof with a fire door 14. A rear side of the firebox 12 is provided with a smoke pipe 16. Surrounding the firebox 12 is a casing 18 which has at least one side thereof, preferably a front side, spaced outwardly of the fire box 12. Also, one end of the casing 18 is spaced from the firebox 12, the end being that remote from the fire door 14. The casing 18 includes a removable cover 20, which may be omitted, if desired.

Secured to the firebox 12 is a draft duct 22. The draft.

duct 22 is disposed in the lower part of the casing 18 and fills a lower part of the corner of the space between the 1 casing 18 and the firebox 12 remote from the fire door 14 and the smoke pipe 16. The'draft duct 22 is gen-- erally L-shaped in plan view and includes an elongated leg 24 and a relatively short leg 26. The relatively short leg 26 has an upwardly projecting extension 28 which communicates with a draft opening 30 formed in the casing 18, as is best illustrated in Figure 8. The extension 28 also includes a partition or bafile wall 32 having an opening 34 therethrough. The opening 34 has mounted therein a damper 36 carried by a pivotally mounted shaft 38. As is best illustrated in Figure 2, the firebox 12 is provided with a draft opening 40 which is housed within the leg 24 of the vent duct 22. Thus, air entering into the extension 28 will pass down into the leg 26, through the leg 24 and into the firebox 12 through the draft opening 40.

In order that the operation of the damper 36 may be automatically controlled, there is provided in the space between the front part of the casing 18 and the front part.

of the firebox 12 a thermostatic control assembly whichv a r ll ing bracket 44 and mounted 'for rotation"with-respect thereto is a horizontal shaft. 46. The shaft 46 has secured thereto for rotation therewith a drive pulley 48. The drive' pulley 48 isaligne'd with =a driven pulley 50-, best illustrated i in Figure 2,'-rnounted on 'the-shaft 38s Entrained over the pulleys-48 and '50 -is a flexibledrive member 52;- The} drive member 5225s secured-to--thepulleys 48-and 50- by suitable clips 54, such as that best-- illustrated in Figure 4 in order to assure movement of the drive member 52 when the drive pulley 48 is rota-ted. Ifdesired, the driven pulley-s50 may-be smaller than .the drive pulley 548 =to --permit a quicker- -re'action;of thedamper 36-for a giv'enmoveme'ntlof the shaft 46.

"Returning onceagain to Figure -'-4' it:- wi-lLbe seen thatthe supporting bracket -.44 terminates{short-of the fireboxv 12. The sha ft 46 project s #b'ey'ond-thesupportingbracket 44 and has mounted thereon a coiled bimetallic member- 56.- The--bimetalli'c memben56 has. an inner end thereof secured to the shaft- 46.-' An outer end oflthe-bimetallic member- 56 isv inthe for-rnof an elongated loop 58 in which is received a-hooked end 60:ofa generally J-shaped support arm-62. Thesupportarm 62passesthroughthe 1 casing 18 and is suitably journaled therein for adjust mentina manner to be described-inmore detail hereinafter..

Inasmuchas-the. bimetallic. member 56-is disposed im-. mediately. adjacentuthefirebox 12, ,itwill be seen that any temperature changes in the firebox 12 will be reflected in mo'vementmof the abimetallicmember 56.. Further, movement-ofthe.bimetallic imernbert56will result in the rotationcfithe shaft-46 inasmuchsas the support arm 62 anchors the other end ofsthe bimetallic member 56.. Since .rhe shaft46..is.connected. tothe shaft.38fby. the pulleys .48. and 50; .and 'theidrive member 52, rotation oftthe,shaft.46zwill.result in the adjustment of the damper 36. in accordance with the temperature of the firebox 12..

In orderthat the desiredtemperature of the firebox 12 may berelatively controlled, the. supportv arm 62 maybe rotatedso as.to..vary the setting, of the bimetallic member 56.v Thiswillresult in the likewse variance of the openingv andclosing of the damper 36 sothatthe temperature ,of thejfirebox 12 may be maintained within a general range by controlling .the setting of the damper 36 through the use ofthe support arm 62-.

The effect of the firebox 12 'up.on the bimetallic element 56.;1I ay also be controlled by the setting of a shield 64 which is disposed between the bimetallic member 56 and the firebox 12.; The shield 64 is carried by a generally L-shaped-mounting arm, 66,. which, like the support arm 62, ,is jo urnaled, in the casing 18., By rotating the mounting arm 66, the, shield64 maybe selectively positioned relative to the birnetallic member 56 so that the effect of the fireboxlZ thereon. maybe selectively varied. In this mannen the relationship of the temperature of the firebox 12 with respectto the bimetallic, member 56 may be further varied.

Referring now toFigure, 6 in particular, it will be seen that the mounting arm .66. has an externally threaded outer portion 68.; Thesportion 68 passesthrough the casing 18. and hassecured thereon a knob 70 which is retained in position by a setscrew.72.; The knob 70 frictionally engages thewoutersurface of the casing 18 and is retained in. such engagement with the casing 18 by a washer 74 mounted on the mounting arm 66 and abutted against a nut 76 adjustably carried by the mounting arm 66. Also carried by the mounting arm 66 and in engagement with the inner surface of the casing 18 is a washer 78. Entr'ained on the mounting arm 66 and compressive- 1y engaged between the washers 74 and 78 is a spring 80 which :controls the frictional engagement of the knob 70'with the casing 18.

Referring now to Figure-7 in particular, it will be seen thatthe knobi 70. includes-a pointenshapedpqrtion 82 1 which cooperates with a dial 784g painted or,otherwise aflixed to the outer surface of the casing 18. The knob 7 7 (Lalso hasan inwardly projecting- .pin 86.-.which.,is..dis'

posed in an arcuate slot 88 formed in the casing 18 to limit the movement of the knob 70.

It is to be understood that the support arm 62 is to be provided with a knob and the spring as well as its cooperating washers 78 and 74,; and the nut 76 so as to operate in identically the same manner as the mounting arm 66. Also, associated with the-knobt70 -of-the support arm 62 is adial 90 i denticalwith thedial- 84.-

Rcferring once again to. Figure 7 insparticular, it ,will be seen that there isformed in the casing 18 adjacent the bimetallic member 56 an opening 92. The opening 92 is provided for the purpose of admitting fresh airto the bimetallic member 56 so; that, the temperature of the outside air will have a controlling effect on the operation of the bimetallic member 56. If desired, the shield 64 may be partially aligned with the opening 92 so as to control the deflection of the cooling air onto the bimetallic member 56.:

Referring now to Figure 2 in particular, it will be seen that the upperpart-of the-firebox 12 isprovided with a damperattachment94. Thedamper-attachment 94 includes a ,sliding damper 96whichcontrols theopening of-.a.draft opening 98 .through the firebox 12. The damper. 96 permitsa desired. amount of-airto enter into the firebox 12 through ordinary louyers in the casing 18-.so thaLs'utficient combustion air-is provided for the uppers part rof the firebox v12 to, eliminate the existence of explosive. gases. The. incoming draft air through the opening.98, ..becauserof its location in the upper part of a the. firebox 12 and opposite to the smoke outlet 16,- both provides air for the combustionaof the explosive gases that accumulate naturallyinside. and at the top of the firebox 12,:: also providea suitabledraft for moving the explosive gases outof-the firebox 12 and up through the smokepipelG .in .situationsawhere. no flameis existent for. combustion, thus preventing gas. accumulations, their ignition and explosionon appearanceof flames in a.

previously. dormant, fire. Continuous clearance of smoke from the firebox 12 is also accomplished thus preventing smoke accumulations.fromissuing through-the fire door 14 when opened.

It is pointed out that the dampers 96 and 36 do not work against each other but due to their relative location on firebox 12, one, at the top and the other at the bottom, they. functionindcpendent of but coordinating with each other. It is-further pointed out that the opening 98 is adjustable so as to, by adjustment of the damper 96, perform its function regardless of the amount of draft the chimney may be capable of producing.

From the foregoing, the construction and operation of the device will; be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications. and changes will readily'occur to thoseskilled in the art, it is not desired, to limit the invention to the exact construction shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the said firebox, an inner end of said bimetallic member. being secured to said shaft, a support arm, said bimetallic member having an outer end connected to said support arm, said support arm being journaled in said casing andextending therethroughto the. exterior of said casing, a control knob on said support arm for setting said bi- 5 6 metallic member, a mounting arm rotatably journaled References Cited in the file of this patent in sairi casing end extending therethrough, a con tro1 knob UNITED STATES PATENTS on sa1d mountlng arm, and a shleld earned by sa1d mounting arm, said shield lying in a plane disposed betwegn 7541275 Barbee Mar. 8, 1904 said firebox and said bimetallic member, sai hi being 5 756,763 ds Apr. 5, 1904 disposable between said firebox and all of aid da r 1,575,188 h fi Mar. 2, 1926 control to vary the temperature effect f id fi b on 1,736,931 hl y Dec. 30, 1930 said damper control, an opening in sa casing adja t 2,143,640 Agrgc la Jan. 10, 1939 said mounting rac et for admitting cool air to said $52222 $532 i e 2; blmetalllc member, B hi ld servmg as a deflector for 1 2,709,551 Bower H May 31, 1955 said cool air. 

